What Causes Pain In Middle Finger?

my middle finger hurts and now my grip is weak and it hurts if i try to pick up anything with my right hand... it hurts all the way up to my shoulder... I am normally physical I am 43 years old... I was trying to work it by squeezing a small ball and even lifting a 5lb weight... The 5lbs id to much for me without hurting it hurts to lift up a glass to drink... i am asking what could be right... i'm normally healthy.